The cynic in me wonders if this is just another desperate attempt by the Tories to grab some previously unattainable votes.
If you've been outside the country longer your likely older. If you've been outside the country longer...and are older, you've probably got a few quid. If you're older and you've got a few quid you likely vote Blue...
I mean, it's not gonna matter right, but still. Cynical.